Abstract

Background

Noncommunicable diseases are an increasing health concern worldwide, but particularly
in low- and middle-income countries. This study quantified and compared education-
and wealth-based inequalities in the prevalence of five noncommunicable diseases (angina,
arthritis, asthma, depression and diabetes) and comorbidity in low- and middle-income
country groups.

Methods

Using 2002–04 World Health Survey data from 41 low- and middle-income countries, the
prevalence estimates of angina, arthritis, asthma, depression, diabetes and comorbidity
in adults aged 18 years or above are presented for wealth quintiles and five education
levels, by sex and country income group. Symptom-based classification was used to
determine angina, arthritis, asthma and depression rates, and diabetes diagnoses were
self-reported. Socioeconomic inequalities according to wealth and education were measured
absolutely, using the slope index of inequality, and relatively, using the relative
index of inequality.

Results

Wealth and education inequalities were more pronounced in the low-income country group
than the middle-income country group. Both wealth and education were inversely associated
with angina, arthritis, asthma, depression and comorbidity prevalence, with strongest
inequalities reported for angina, asthma and comorbidity. Diabetes prevalence was
positively associated with wealth and, to a lesser extent, education. Adjustments
for confounding variables tended to decrease the magnitude of the inequality.

Conclusions

Noncommunicable diseases are not necessarily diseases of the wealthy, and showed unequal
distribution across socioeconomic groups in low- and middle-income country groups.
Disaggregated research is warranted to assess the impact of individual noncommunicable
diseases according to socioeconomic indicators.